Combined shield plate, dial, and vernier



c. J. HENSCHEL COMBINED SHIELD PLATE, DIAL, AND VERNIER Filed June 15,

\ T-IEURE 1. 6

351 Gum W45 Patented Dec. 8, 1925.

UNITED STATES CHARLES J. HENSGHEL, OF ARLINGTON, NEW JERSEY.

COMBINED SHIELD PLATE, DIAL, AND VERNIER.

Application filed June 15, 1922. Serial No. 568,589.

To all whom it may concern:

Be it known that I, CHAnLns J HnNsoHnL, a citizen of the United States, residing in Arlington, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Combined Shield Plates, Dials, and Verniers, of which provided with verniers, but so far as I knowdials, either with or without vendors, have not been employed in immediatev and direct association with shield plates.

What I seek more particularly to do,"

therefore, is to use, in connection with a dial and'a Vernier-for obtaining fine adjustments therewith. a shield .plate made of metal or other conducting material and grounded,

the shield plate being located in close prox:

imity'to both the dial and thevernier mechanism, and so arrangedas to prevent the body capacity of the operator from affecting any delicate ra dio mechanism connected with the dial and Vernier, and controllable there- It is a fact wellknown in this art that radio sets, such for instance as are usedin connection with broadcasting receivers, constantly need adjustment; and that such ad justment is usually accomplished by means of dials, operatedbyhand for this purpose. It is also a well known fact that certain delicate parts of the radio'mechanism are very sensitive to various kinds. of disturbing influences, and that prominent among these is the body capacity of the operator. To ex lain further, when the operator places his hand upon the knob or any other portion of a dial, or of any mechanism in close proximity to the 'dial,he is apt. to disturb the working of the radio set. This is because of the fact that his body has quite a large capacity, andthis capacity enters as a disturbing factor and tends to destroy thcequilibrium of the radio-set and thus cause the set to work badly. Moreover an adjustment made, and made accurately,

while the o erato'r has a hand engaging the knob of a dial will not remain accurate after the removal of the operators hand. This is because the adjustment is made while the radio set is affected by a certain amount of capacitywhich for the moment is greater than usual, and which is. immediately lessened when the operator removes hishand from the apparatus.

I find that it 'is. practicable to use a shield plate made ofmetal and so located relatively to the dial and other parts immediatelyassociated therewith, as to prevent any and all disturbing effects arising from the static capacity of the operators body, due to his grasping and releasing the knob of the dial.

Reference is made to the accompanying drawing forming a part of this specification', and in which like reference characters indicate like parts throughout the several figures. f

Figure 1 is a substantiallycentral vertical section through the wall of a casing to which my device is applied. 1

Figure 2 is a front elevation of the shield I plate, dial and vernier.

Figure 3 is a section on the line 33 of Figural, looking in the direction indicated by the arrows, the casing wall being omitted.

A shield plate is'shown at 6, and is made of metal. The shield plate is provided with arim 7, havinga bevel edge 8, provided with graduations 9.

A dial is shown at 10, and is made of insulating material, such as bakelite, hard I rubber, fiber or any of the well known compositions usually employedforinsulation of this general character. The dial 10 is pro' vided with a hub portion 11, extending 'll'ltO' the hole 5 of the casing, and also extending through a hole 12 with which the shield plate 6 is provided. The dial 1( has also'a bevel edge 13, and graduations'14 carried by this edge. The graduations 14 upon the dial 10 are related to the graduations 9 upon the shield" plate 7, in such manner as to co-act therewith as with a Vernier scale. I

' The dial 10 carries a knob 15 integral with it, and adapted to be grasped by the operator. The dial carries a revoluhle shaft 10*,

extending axially from it and held in position by a set screw 10, as indicated more particularly in Figure 1. The-shaft 10' extends within the casing, and may be connected with any movable part of a radio set,

to enable the part in uestion to be adjusted against the edge 16 firmly, but not too tightly, with the parts arranged as indicated in Figure 1. The ring 17 of soft rubber may be very easily andcheaply made, as for in-' stance by cutting off a short length of ordinary rubber tubing. It is fitted tightly upon ameter, and being threaded as indicated at the left of Figure 1. Fitted upon the por:

tion 20 are nuts 21, 22, and supported byv these nuts and by the portion 20 is a bit of sheet metal 23. Connected with this sheet metal is a wire 24, leading to the groundfat 25. The bolt 18 is in engagement with the shield plate 6. A rubber washer 25, sunken in an opening 26, encircles the portion 20 of the bolt 18. A micrometer adjustment knob appears at 27, and-carries a tubular stem 28 upon which the ring 17 of soft rubber is fitted tightly. The micrometer adjustment knob 27 and the tubular stem 28 are integral, and are made of insulating material as above described in connection with the dial 10. The knob 27 is provided with a bore 29, so

proportioned and arranged as to partially house the head 19 wherever the knob 27 and parts carried thereby are grasped by hand and pulled outwardly a little-that is, drawn to the right according to Figure 1.

Starting with the parts occupying the positions indicated for them in Figure 1, the operator can grasp the knob 27 by hand and by pulling upon it can slide the tubular stem 28 to the right according to Figure 1, so that the ring -17 is drawn out of engagement with the adjacent peripheral edge of the dial. This done, the operator can grasp the knob 15 and turn the dial 10 quickly and to any desired extent in either of two directions. The operator can now press the knob 27 back into position, and thus bring the rubber ring 17 back into engagement with the periph' eral edge 16 of the dial; or in other words bring the various movable parts into the position indicated for them at the lower part of Figure 1. g

If, now, the operator desires to make an exceptionally accurate adjustment of the dial 10, he simply turns the knob 27, and meanwhile notes the registry of the graduations 14 and 9 as above described.

Thus it is practicable for the operator to make either-a quick and somewhat coarse adjustment, or a slower but more accurate adjustment, as desired.

With the movable parts of the device occupying the positions indicated for them in Figure 1, the rubber ring .17 serves as a lock for preventing accidental displacement of the dial, and thus has a tendency to hold any adjustment securely after it is made.

The shield plate 6, being always grounded A bolt 18, is prothrough the wire 24 as above described, is

operator grasps either one of the knobs 15 or 27 for any purpose, the capacity of his body can have no effect upon any mechanism inside of the casing.

I do not limit myself to the precise mechanism shown, as variations may be made therein without departing from my-invention the scope of which is commensurate with my claims.

"I claim:

I '1. A-device of the character described,-

comprising a, shield plate provided with a thickened edge and having an indication thereon, means'for grounding said shield plate, and a dial made of insulating material and revolubly mounted upon said shield plate, said dial being provlded with an indicator portion registering with the iridication upon thickened edge of the shield ate. P 2. The combination of a casing wall provided with an opening, a metallic shield plate engaging said casing wall and provided with an opening registering with the opening in the casing wall, a dial provided with a portion extending through the opening in the shield plate and into the opening in the casing wall, and means for grounding said shield plate.

' 3. A device of' the character described comprisinga casing wall, a shield plate,

engaging said casing wall,'a dial revolubly mounted upon said shield plate and provided with a knob for enabling the dial to be turned directly by hand, a bolt engaging saidshield plate, a ground connection for said bolt and said shield plate, and a micrometer adjustment device supported by said bolt and engaging said'dial for the purpose of enabling the operator to turn the dial by aid of the device.

4. A device of the character described comprising a shield plate of conducting material, a ground connection for said shield, a dial disposed adjacent said shield and revoluble relatively thereto, and a micrometer adjustment device detachably engaging said dial for the purpose of enabling the operator to turn the dial directly or by aid of the device, as desired.

5. The combination of a shield plate of conducting material, a dial revolubly en- .gaging said shield and provided with a; knob for enabling the operator to turn the dial directly, a rubber ring detachably engaging the edge of the dial, a stem revolubly mounted upon the shield plate and disposed adjacent the dial, said stem carrying said rubber ring in order to enable the operator to turn the dial by aid of the rubber ring, and mechanism controllable at the will of the operator for enabling him to Withdraw the rubber ring from engagement With the dial.

6. A device of the character described comprisinga casing Wall, a shield plate made of conducting material and engaging said casing wall, a dial revolubly mounted upon said shield plate and made of insulating material, a bolt extending through said shield plate, a ground connection for said bolt, a revoluble stem mounted upon said bolt and provided with a knob for turning said stem, said stern bein movable by hand in the direction of the length of the bolt, and a rubber ring mounted upon said stem and movable by the same into and out of engagement with the dial.

onnnnne J. nnnsennn 

